Marzipan is the code name for Apple’s multi-year project to bring UIKit apps to the macOS. In other words, apps made in the newfangled iPad way, rather than the traditional AppKit way for the Mac.
We saw the awkward early stages last year at WWDC 2018 with the release of Apple’s first iPad app ports, News, Home, Voice Recorder, and Stocks for macOS. And while they’re not good, or consistent, or inspiring, or good, at least not yet. They’re most definitely there.
Apple said stage two begins this year, at WWDC 2019, when developers get their chance to creating and porting UKit apps to the Mac. Sure, that includes huge players like Netflix and Twitter, and more feature-complete versions of Apple’s own apps like Photos and Messages, it could also include iOS apps that previously made no economic sense to redo for the Mac, like Drafts and Overcast.
Most recently, Mark Gurman rumored for Bloomberg that future stages also include a way to bring iPhone apps — the ones without existing iPad interfaces — over as well, and, eventually, a unified App Store and universal binaries across iPhone, iPad, Mac, and Apple’s existing adjunct platforms, like Watch, TV, and maybe even CarPlay.
But it’s a long road from here to there, and I’m not a developer, so I reached out to one of the smartest, most industries, most keyed-in developers I know to help me suss all this out.